The present invention relates to a display device using an electrochromic substance (hereafter referred to as an EC material) and a driving method thereof. More particularly, the present invention relates to a driving system for transferring a coloration electric charge held in electrodes in a coloration state to electrodes in a bleaching state (hereinafter referred to as an electric charge transfer drive) by applying a voltage therebetween.
The conventional EC display device driven by the electric charge transfer drive technique is advantageous in that it is driven by a single power source, the display does not exhibit color shading and the response time is quick. However, there is a disadvantage that the conventional EC display device necessitates the use of display dummy electrodes for constantly equalizing the number of the display electrodes which changes into the colored state to the number of display electrodes which changes into the bleached state, for the sake of eliminating the non-uniformity of coloration density caused by the electric charge transfer. Therefore the display area of the display electrodes is somewhat limited.